1. Field of the Invention
This invention relates generally to circuit breakers having more than one microswitch for providing an indication of the operating status of the circuit breaker and, more particularly, to the mechanism for simultaneously actuating the microswitches.
2. Background Information
Large multi-pole circuit breakers typically have a crossbar which links the poles together and opens the contacts in all phases if any phase trips open. Often, a microswitch, such as an auxiliary switch, is provided in such breakers to generate an external indication that the contacts are open such as for electrical interlocks between multiple circuit breakers or for remote monitoring of circuit breaker operation. Since the crossbar provides an indication of the state of the circuit breaker contacts, either opened or closed, the crossbar has been used to actuate the auxiliary switch. In some circuit breakers an additional microswitch, such as a bell alarm switch, is included which is actuated when the circuit breaker is tripped, again for remote monitoring of breaker operation.
The small circuit breakers used for residential and light commercial or industrial use do not typically have a crossbar with which a microswitch may work in cooperation to indicate the operating status of the breaker, namely because they are single pole. Adding microswitches to such small circuit breakers has been found to be difficult because such breakers typically have limited space due to their configuration for mounting in a standardized load center or panel board. U.S. Pat. No. 5,552,755 discloses an example of a small residential or light industrial or commercial circuit breaker which is provided with a microswitch to generate an electrical indication that the circuit breaker contacts are opened. Cascaded actuating members, one actuated by handle structure and one by the cradle, are incorporated into the circuit breaker for actuating a plunger of the microswitch and indicating the operating status of the breaker. However, the cascaded actuating member, while effective for actuating a single microswitch, is unable to effectively actuate two microswitches, or possibly more than two microswitches, that may be ganged together for indicating the operating status of the breaker or providing other functions which are generally known in the art.
There remains a need, therefore, for a small residential or light industrial or commercial circuit breaker which is provided with more than one microswitch for indicating the operating status of the breaker.
There is also a need for a small residential or light industrial or commercial circuit breaker having more than one microswitch where the microswitches may be simultaneously actuated. This must be accomplished within a standardized size of such circuit breakers so that they may be continued to be used in the standard load centers and panel boards.